Method and device for realizing stable plasma confinement by pressure of AC magnetic field which can be used for controlled nuclear fusion

Abstract

The invention relates to method and devices for producing stable hot plasma. In particular, the invention can be applied for realizing stable plasma in a thermonuclear reactor to provide energy source for power generation. In the method plasma is confined by pressure of AC magnetic field concentrated in a layer between plasma surface and surrounding conducting shell in which stabilizing feedback on the confined plasma is created by achieving conservation of the AC magnetic flux amplitude. The device for realization of the proposed method comprises a toroidal conducting shell filled with plasma, with AC voltages applied to insulated cuts in the shell made in poloidal and toroidal directions such that said AC magnetic field is created by AC currents in the shell and image currents on the plasma surface. The amplitudes and relative phases of said voltages are rather arbitrary, in particular they can be selected such that the resultant magnetic vector rotates in the plane tangential to the plasma surface with nearly circular polarization exerting nearly time independent magnetic pressure on the plasma.

1 . A method of plasma creation and stable confinement by pressure of AC electric and magnetic fields, with the frequency of said fields such that the size of the confined plasma is substantially smaller than the wave length of electromagnetic wave propagating in vacuum with the same frequency, with polarization of said magnetic field being different from linear, with special feedback arrangement between perturbations of plasma boundary and said electromagnetic field such that said feedback produces a stabilizing effect on said plasma boundary. 
   
   
       2 . The method as claimed in  claim 1 , in which said feedback is realized by means of approximate conservation of amplitude of AC magnetic flux localized in a layer between boundary of said plasma and wall of confining chamber. 
   
   
       3 . The method as claimed in  claim 1 , in which said feedback is realized by generating said AC magnetic field by means of driving AC currents directly in conducting shell surrounding plasma volume. 
   
   
       4 . The method in  claim 1  used in application selected from the group of: destroying gaseous toxic waste, processing semiconductors, generating reactive gases, enhancing gaseous chemical processes, plasma sources, generating optical, ultraviolet and X-ray radiation, generating neutrons derived from fusion reactions, conducting nuclear fusion reactions, confining fusion grade plasmas in thermonuclear reactors to provide energy source for power generation. 
   
   
       5 . A method of producing and confining plasma in which an electric discharge is generated in a gaseous working medium inside a chamber by subjecting said medium to the action of electromagnetic oscillations, with wall of said chamber having a generally toroidal topology, said toroidal topology defining a torus with a hole, a cyclic toroidal direction encircling said hole, and a cyclic poloidal direction generally orthogonal to said toroidal direction, with the frequency of said oscillations such that the minor radius of said chamber is substantially smaller than the wave length of electromagnetic wave propagating in vacuum with the same frequency, with amplitudes of AC magnetic field in said electromagnetic oscillations having nonzero components in the poloidal and toroidal directions inside said chamber in the vicinity of said wall, with said AC magnetic field generated by AC currents driven in said wall of said chamber and by image currents in said plasma. 
   
   
       6 . A device for producing and confining plasma comprising:
 a. a toroidal chamber adapted for receiving working gasses and for containing said plasma,   b. a chamber wall in a form of a shell having a generally toroidal topology, said toroidal topology defining a torus with a hole, a cyclic toroidal direction encircling said hole, and a cyclic poloidal direction generally orthogonal to said toroidal direction, said shell made from an electrically conducting material, with two narrow cuts in said shell made in substantially toroidal and poloidal directions and sealed with a dielectric material such that no gas or plasma can pass through said cuts and there is no electrical continuity of said shell in toroidal and poloidal directions,   c. AC power sources, generating voltages with the same frequency and nonzero amplitudes, with said power sources connected across said toroidal and poloidal cuts in said shell via transmission lines,   
     whereby plasma discharge is created by inductive electric field induced by AC magnetic field, said AC power sources drive toroidal and poloidal AC currents in said shell and corresponding image currents in said plasma, with said currents generating AC magnetic field inside said chamber which exerts pressure on said plasma and confines the latter. 
   
   
       7 . A device as claimed in  claim 6 , with arrangement for uniform application of AC voltages, supplied by said AC power sources, along said toroidal and poloidal cuts in said shell. 
   
   
       8 . A device as claimed in  claim 6 , with arrangement for uniform application of AC voltages, supplied by said AC power sources, along said toroidal and poloidal cuts in said shell comprising multiple transmission lines originating at said AC power sources and terminating accordingly at different toroidal and poloidal locations along said cuts in said shell. 
   
   
       9 . A device as claimed in  claim 6 , in which said toroidal shell with said chamber filled with said plasma is a part of a radio-frequency circuit, with said circuit including an AC generator, with said AC power sources supplying voltages to said cuts in said shell schematically representing parts of said radio-frequency circuit. 
   
   
       10 . A device as claimed in  claim 9 , in which the frequency of said AC generator is close to natural frequency of oscillations of said radio-frequency circuit. 
   
   
       11 . A device as claimed in  claim 6 , in which multiple toroidal and poloidal cuts are made in said shell at different poloidal and toroidal locations, said cuts are sealed with a dielectric material, with AC voltages of nonzero amplitudes applied across said cuts. 
   
   
       12 . A device as claimed in  claim 6 , with said AC power sources operating in a regime selected from the group of: a steady-state regime with nearly time independent amplitudes of said voltages, a pulsed mode with the amplitudes of said voltages forming an envelope lasting several periods of oscillations. 
   
   
       13 . A device as claimed in  claim 6 , with said AC power sources supplying generally periodic voltages to said cuts in said shell. 
   
   
       14 . A device as claimed in  claim 6 , with said AC power sources supplying voltages to said poloidal and toroidal cuts in said shell with the ratio of said voltages approximately equal to the ratio of major and minor radii of said toroidal chamber with 90° phase difference between said voltages. 
   
   
       15 . A device as claimed in  claim 6 , with said AC power sources supplying arbitrary nonzero voltages to said poloidal and toroidal cuts in said shell with arbitrary phase difference between said voltages. 
   
   
       16 . A device as claimed in  claim 6 , in which a layer of solid dielectric is placed along the inner surface of said toroidal shell, with said dielectric layer covering all inner surface area of said shell. 
   
   
       17 . A device as claimed in  claim 16 , in which said layer of solid dielectric serves as a wall of said chamber, with said conducting shell replaced by a grid of closely spaced inter-connected conducting wires covering the outer surface of said dielectric layer, with electrical brakes made in said grid of wires along the positions of said toroidal and poloidal cuts to which the AC voltages, supplied by said AC power sources, are applied. 
   
   
       18 . A device as claimed in  claim 6 , with a limiter limiting the radius of said plasma, with said limiter made from either conducting or dielectric material in a form of one or several ledges extending in toroidal or poloidal directions along the inner surface of said shell. 
   
   
       19 . A device as claimed in  claim 6 , in which said toroidal shell is made from superconducting material with additional arrangement designed to remove heat generated in said plasma comprising:
 a. a layer of low loss solid dielectric with high thermal conductivity which forms a plasma facing wall of said toroidal chamber,   b. a layer of low loss solid dielectric with low thermal conductivity placed along the inner surface of said superconducting shell and used for thermal isolation of said shell,   c. a layer of liquid dielectric flowing in the cavity between said dielectric layers, with said liquid dielectric used as a coolant to remove heat deposited in said plasma facing dielectric layer,   d. means to introduce the flow of said liquid dielectric coolant.   
   
   
       20 . A device as claimed in  claim 19 , in which said flow of said liquid dielectric coolant is introduced through said toroidal or poloidal cuts in said shell or through manifolds connected in other places. 
   
   
       21 . A device as claimed in  claim 19 , in which said plasma is created and confined at such density and temperature that fusion reactions are used to provide energy source for power generation.